【摘要】 为了研究TBM盘形滚刀在不同动静载荷组合作用下切削花岗岩过程中的切削特性,在动静载荷组合作用下对盘形滚刀进行受力分析,采用颗粒离散元法建立岩石破碎全过程的二维数值模型,研究破岩过程岩石内部的裂纹扩展情况、内应力分布情况以及盘形滚刀的贯入度和破岩比能耗,分析在不同动静载荷组合作用下盘形滚刀破岩的情形,得到破岩效果最优的动静载荷组合。研究结果表明:随着静载荷和冲击动载荷增加,盘形滚刀的贯入度增加;盘形滚刀在动静载荷组合作用下破岩过程分为3个阶段,岩石内部应力基本符合J.Boussinesq应力圆规律;动静组合载荷作用下,岩石内部萌发的侧向裂纹比中间裂纹扩展得更快,以受拉破坏为主;破碎体积、贯入度和破岩效率相对于单一静载或单一动载有很大的提高;合理选取动静组合载荷能使破岩比能耗最小,破岩效果最好。更多还原

【Abstract】 In order to study the cutting characteristics of TBM disc cutter while disc cutter is cutting granite under the combined dynamic and static loading, the force of disc cutter was analyzed and a two-dimensional numerical simulation model was established based on the particle discrete element method. The crack propagation and stress distribution of rock, broken-volume, penetration depth and specific energy consumption were analyzed. By Studying the patterns of breaking rock at different dynamic and static stress levels, an optimal combined loading existed which can make the specific energy consumption least and breaking effect optimal. A mathematical mechanical model of disc cutter and a two-dimensional numerical simulation model of breaking rock were established. The results show that the penetration depth increases with the increase of static load and dynamic load. Under the combined dynamic and static loading, the process of breaking rock undergoes three steps and stress distribution of rock corresponds to J.Boussinesq equations. The lateral crack growth rate is faster than that of the middle crack and the rock is given priority to with tensile failure.Meanwhile, the rock breaking effects are greatly improved in the broken-volume, penetration depth and specific energy consumption compared with constant static loading and impact dynamic loading. There is an optimal combined loading existing, which can make the specific energy consumption least and breaking effect optimal.更多还原